Conservative leader Ruth Davidson has announced plans to take her party down the route of extended devolution for Scotland little more than a year after she ruled out such a move.

However, Ms Davidson's call for the Conservatives to play a part in the public's "appetite for change" through possible greater tax powers was met by a sardonic response from her defeated leadership opponent Murdo Fraser.

He had called for greater tax powers for Holyrood during their 2011 contest, but at the time was attacked on the issue by Ms Davidson.

He tweeted: "Looks like a very good speech from Ruth Davidson. Could almost have written it myself."

Ms Davidson told supporters in Edinburgh: "The debate has moved a great deal in the last year. We now know what the parameters are for a referendum on independence. But the conversation on the constitutional future of Scotland doesn't begin and end with that referendum.

"It will continue and the Scottish Conservatives must have a voice, a strong and positive voice, in that conversation."

Some of Mr Fraser's supporters questioned whether the policy change was her own, or whether it was being pushed from Downing Street where there may be more of a recognition that next year's independence referendum offers scope for a grand gesture.

This could get Scots Tories out of the bind they have been in ever since opposing Home Rule at the 1997 referendum.

Ms Davidson suggested the Conservatives are unforgiven for the party's past opposition to devolution and its perceived anti-Scottishness.

However, for a politician defined by her pledge to make the Calman reforms a "line in the sand" with no further change to the devolution settlement, she spoke of the "need to embrace reform with a true sense of belief in a positive future for Scotland's institutions".

She added: "At the referendum next year, Scotland will vote, but it will not be, must not be, a vote pitting 'change' against 'no change'. There is an appetite for change and by recognising we can play our part in bringing Scotland back together after what will unquestionably be a campaign of the highest emotions.

"Change is coming and the Scottish Conservatives will be enthusiastic advocates for that change – the positive change that Scotland needs."

There were two other key points in her speech – repeated references to the powers of states in the US. She also referred in particular to the US states of North Carolina, New York and Texas, which hinted at support for a federal system.

In reinforcing her points about the Tories losing touch with the mood in Scotland she cited her own age, just six months old at the time of the 1979 referendum, and a teenager in 1997.

She spoke of older Conservatives as "products of their environment" born into a past era when the Tories commanded popular support. She revealed she had voted No-Yes in 1997, against the Parliament, but in favour of it having tax powers to make it responsible.

It is now clear, she said, the majority "want to see the Scottish Parliament assume more responsibility and that will not disappear after the referendum".

The SNP's Annabelle Ewing said: "After a year in office she has nothing to offer except the rebrand promised by her defeated opponent for the leadership.

"The problem for the Tories is not just that the people of Scotland don't like their message – it's that they fundamentally don't trust the Tories."

Labour said: "This is less of a U-turn and more of a pirouette. It is understandable she wants to get as far away from David Cameron as possible but this looks less like a policymaking process and more a game of spin the bottle. Perhaps if Ruth had her time again she would vote for Murdo Fraser as leader since this seems a lot closer to his manifesto than her's."